Biosystematic Studies of Gramineae and Cyperaceae in Nepal

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1.Cytotaxonomic study. In this research, we collected about 1200 herbarium specimens of Gramineae and Cyperaceae. We counted the chromosome number of 31 species of 12 genera in Gramineae and 13 species of four genera in Cyperaceae・ The species of genus Carex and Kobresia were differenciated in many cytological forms in Himalaya alpine region. 2.Pollen analysis. The investigated part of the core covers approximately the last 6000 years of the Holocene. The main parts of the vegetational history and the climatic change in Nepal can be regarded to corespond them in Japan. 3.Relationship between vegetation and the topographical environment. On the stable places, Kobresia nepalensis was dominant but the unstable place K.pygmaea was dominant. These two common species are believed to have different mechanism for adaptive evolution. 4.Plant defense guild observed on a talus. Plant communities on a talus showed a clear diffentiation according to the topography. Since Kobresia nepalensis was preferred and Potentilla obliqua was disliked by livestock, other co-growing plants were shorter on the slope than at the lower end. This is a good example of the "plant defense guild" proposed by Atsatt & O'Dowd (1976). 5.Chemical constituents of genus Kobresia. The presences of those highly oxygenated compounds may be considered as indicator of species differentiation in the genus Kobresia. Some of them was found to show antimicrobial activity and moderately insecticidal activity.